无向图的生成树

#include<stdio.h>
#include<stdlib.h>
#define MAX 20
#define OVERFLOW -2
typedef char VertexType;
typedef struct ArcNode
{
int adjvex;
struct ArcNode *nextarc;
}ArcNode;
typedef struct VNode
{
VertexType data;
int mark;
ArcNode *firstarc;
}VNode,AdjList[MAX];
typedef struct
{
AdjList vertices;
int vexnum,arcnum;
}ALGraph;
typedef struct Node
{
struct Node *child,*nextsibling;
VertexType data;
}Node,*CSTree;
void Create(ALGraph &G);
int LocateVex(ALGraph G,char v);
void DFSForest(ALGraph &G,CSTree &T);
void DFSTree(ALGraph G,int v,CSTree &T);
int FirstAdjVex(ALGraph G,int v);
int NextAdjVex(ALGraph G,int v,int w);
void Output(CSTree T);
void main()
{
ALGraph G;
CSTree T;
Create(G);
DFSForest(G,T);
printf("\n\n\n\n无向图的生成树的中序遍历:");
Output(T);
printf("\n\n\n\n\n\n\n");
}
void Create(ALGraph &G)
{
int i,j,k,flag1,flag2;
char v1,v2;
ArcNode *p1,*p2,*p3,*p4;
p1=p2=p3=p4=NULL;
printf("请输入顶点数和边数:");
scanf("%d %d",&G.vexnum,&G.arcnum);
flushall();
printf("\n\n请输入顶点(字符间不要空格):");
for(i=0;i<G.vexnum;i++)
{
scanf("%c",&G.vertices[i].data);
G.vertices[i].firstarc=NULL;
}
system("cls");
for(k=0;k<G.arcnum;k++)
{
printf("请输入边上的两个顶点(顶点间不要空格):");
flushall();
scanf("%c%c",&v1,&v2);
printf("\n\n");
i=LocateVex(G,v1);
j=LocateVex(G,v2);
p3=(ArcNode *)malloc(sizeof(ArcNode));
if(!p3)
exit(OVERFLOW);
p4=(ArcNode *)malloc(sizeof(ArcNode));
if(!p4)
exit(OVERFLOW);
p3->adjvex=j;
p3->nextarc=NULL;
p4->adjvex=i;
p4->nextarc=NULL;
flag1=flag2=0;
if(G.vertices[i].firstarc)
{
p1=G.vertices[i].firstarc;
flag1=1;
while(p1->nextarc)
p1=p1->nextarc;
}
if(G.vertices[j].firstarc)
{
p2=G.vertices[j].firstarc;
flag2=1;
while(p2->nextarc)
p2=p2->nextarc;
}
if(flag1==0)
G.vertices[i].firstarc=p3;
else
p1->nextarc=p3;
if(flag2==0)
G.vertices[j].firstarc=p4;
else
p2->nextarc=p4;
}
}
int LocateVex(ALGraph G,char v)
{
int i=0;
while(G.vertices[i].data!=v)
i++;
return i;
}
void DFSForest(ALGraph &G,CSTree &T)
{
int v,first=0;
CSTree p,q;
T=NULL;
for(v=0;v<G.vexnum;v++)
G.vertices[v].mark=0;
for(v=0;v<G.vexnum;v++)
{
if(!G.vertices[v].mark)
{
p=(CSTree)malloc(sizeof(Node));
if(!p)
exit(-1);
p->data=G.vertices[v].data;
p->child=p->nextsibling=NULL;
if(!T)
T=p;
else
q->nextsibling=p;
q=p;
DFSTree(G,v,p);
}
}
}
void DFSTree(ALGraph G,int v,CSTree &T)
{
int w,first=0;
CSTree p,q;
G.vertices[v].mark=1;
for(w=FirstAdjVex(G,v);w>=0;w=NextAdjVex(G,v,w)) {
if(!G.vertices[v].mark)
{
p=(CSTree)malloc(sizeof(Node));
if(!p)
exit(-1);
p->data=G.vertices[v].data;
p->child=p->nextsibling=NULL;
if(first)
{
T->child=p;
first=1;
}
else
q->nextsibling=p;
q=p;
DFSTree(G,v,q);
}
}
}
int FirstAdjVex(ALGraph G,int v)
{
int w;
if(G.vertices[v].firstarc)
{
w=G.vertices[v].firstarc->adjvex;
return w;
}
return -1;
}
int NextAdjVex(ALGraph G,int v,int w)
{
ArcNode *p;
p=G.vertices[v].firstarc;
while(p->adjvex!=w)
p=p->nextarc;
if(p->nextarc)
return p->nextarc->adjvex;
else
return -1;
}
void Output(CSTree T)
{
if(T)
{
Output(T->child);
printf("%c ",T->data);
Output(T->nextsibling);
}
}。